Hey Googlers, what is the significance of 7bbb41211116? | Hacker News Reader

Hey Googlers, what is the significance of 7bbb41211116?

11 pointsarthurcolle8 comments

https://stackoverflow.com/questions/52729609/domain-name-wit...

I just posted that...

Well, IP addresses are just numbers, so you could convert that to an IP address, then do a whois lookup if you wanted.

7bbb41211116 => 136044181786902 => 65.33.17.22

ARIN shows that as a Roadrunner IP, so I'm not so sure that's the right answer. Unless that's actually the OP's IP address on RR and it was auto-detected and plugged in programmatically somehow.

It's the right length for a mac address:

7b:bb:41:21:11:16

As you can see from the SO question that was posted as a comment, I am running the TF Docker image and figured that it must be an internal domain - I didn't realize this was a thing, but on deeper reflection, since blog.google evidences custom TLDs (ccTLDs iirc) I'm a bit confused why everyone can't have their own TLD and be able to run their own internal networks. Guessed it was related to Google's internal domain(s). How does one establish your own TLD domain? Can you just make it happen yourself without paying anyone else? I mean after all I have all these computers that are sitting unused, it seems technically feasible to deploy my own network and write adapters to make it just compatible enough with the rest of the Internet to get what I need in terms of information

You can create whatever arbitrary naming convention you want for internal networks, and use either hosts files or your own private DNS server to resolve those names. But if your scheme overlaps with something that's published publicly, it's probably going to cause problems at some point.

There's a little bit of info in some RFC's about special / reserved names, which are dedicated to certain special uses. See, for example:

https://tools.ietf.org/html/rfc6761

https://tools.ietf.org/html/rfc2606

In years past, a lot of people would just pick a tld that didn't exist and then use that for internal domain names. That was probably safe back when new TLD's came into existence very infrequently. In this day and age, TLD squatting is a risky proposition, as seen here:

https://medium.engineering/use-a-dev-domain-not-anymore-9521...

7b has both LSBs set. That makes it multicast and locally administered. ergo, unlikely to be a mac address.

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